Minimized drag tow target construction



v Filed may 4. 195s Oct'. 27, 1959 E. FRI-:Y 2,910,096

MINTMIZED DRAG Tow TARGET CONSTRUCTION ATToR'zmYs Oct. 27, 1959 E. FREY2,910,096

MINIMIZED DRAG rTow TARGET CONSTRUCTION Filed May 4. 195e 2 sheets-sheet2 #i Ri IN VEN TOR.

Elia/wld Frey limited States Patent v .2,910,096 NIINIMIZED DRAG TOWTARGET CONSTRUCTION Edward Frey, Akron, Ohio, assignor to The Massillon-Cleveland-Akron Sign Company, Massillon, Ohio, a corporation of OhioApplication May 4, 1956, Serial No. 582,749

3 Claims. (Cl. 139-419) The invention relates to minimized drag towtarget construction of the banner type, and constitutes improvements ofthe tow target construction set forth in my prior application for UnitedStates Letters Patent, Serial No. 554,977, tiled December 23, 1955, nowPatent No. 2,807,287.

Banner type tow targets are used for training Armed Forces personnel ingun, cannon, rocket, and missile marksmanship. A banner type tow targetfor such purpose is connected by a tow line of required length to atowing aircraft. The marksman trainee operates from another aircraftmiles away. The aircraft bearing the marksman trainee is termed herein aweapon system for convenience, but actually may be any type of aircraft,from a low-powered, low-speed training plane, to a highpowered,high-speed fighter plane.

Prior to the banner type tow target construction set forth in my saidapplication for United States Letters Patent, Serial No. 554,977, nowU.S. Patent No. 2,807,287, diiiiculties have been encountered inproducing banner type tow targets having a useful life of sutlicientlength to minimize the cost of each training mission, and which areotherwise satisfactory, even at relatively low altitudes and low speedsof tow target travel. Y

Prior banner type tow targets have been made of various types of openmesh flexible fabric material and have been upwards of nine (9) feetwide by forty-five (45) feet long. The forward end of the target may betermed the leading edge, and is connected by a hitch to the reareend ofthe tow line. The rear end of the tow target may be termed the trailingedge.

@In use, the forward portion of a banner type tow target assumes a moreor less flat horizontal position which extends to as much as one-third(1A) of the total length of the target. The middle portion of thetarget, which may extend another one-third (lf3) of the total length off the target, assumes a condition of rippling in undulating waves havingpeaks and valleys which extend transversely of the direction of flight.The rear portion of the target, which may extend the finalone-third(1/3) of the total length of the target, assumes a condition of whippingor apping, which is very damaging to the material of the target in thiswhipping portion of the target.

'I'he ditliculties encountered in prior banner type tow targetconstructions include the following:

First: -For the purpose of minimizing the power re-V quired in thetowing airplane, it is desirable to minimize the total drag of thetarget. A target made of material having a weight suliicient to reducerippling and whipping to a satisfactory degree, has a drag which becomesprohibitive,

Second: As the speed of the tow target is Vincreased for trainingmarksmen operating from the -higher speed weapon systems, the greaterthe increase in target speed, the greater theA drag created by theundesirable rippling and whipping of the target.

Third: (1) A high' speed weapon system is manui P l CC 2 Y ally orautomatically controlled until contact is made with the target, then aradar operated electronic control system locks on the target, andoperates the weapon system, until the target has been fired on, orpassed by. Personnel operating a weapon system must be trained incarrying out the weapon system objective. (2) Tow targets of priorconstruction frequently have been made of materials having'no radarreecting properties. To overcome this, radar reflecting corners havebeen attached to the forward end of such targets, with results that havenot been satisfactory. Corner reliectors create greatly increased dragon the tow airplane, and have limiting factors undesirably affectingpresent radar and tire control systems. (3)` Prior banner type towtargets which have been made ofy metallized fabrics have been excessivein weight and drag, and have been subject to operational objectionssimilar to those incident to the use of radar reflecting corners.

Banner type tow targets including the improvements set forth in my saidprior application for United States Letters Patent, Serial No. 554,977,ily satisfactorily at a true air speed of 385 miles per hour ataltitudes as high as 30,000 feet.

Requirements of the Armed Forces for 1956 and thereafter, specify abanner type tow target which will ily at altitudes of 30,000 feet andupwards, at indicated air speeds of 250 knots per hour and upwards, withthe vrequired durability and low drag characteristics; and such a towtarget must be made of material that is radar reflective. s

The objects of the present invention include the provision of a bannertype tow target including certain of the improvements of my said priorapplication for United States Letters Patent, Serial No. 554,977, andincluding other improvements enabling the tow target to meet therequirements of the Armed -Forces for 1956 and thereafter, as `above setforth. e

A further object of the present invention is the provision of such abanner type tow target which may be made of differential weave openwoven fabric in vcontinuous lengths without cross-seams. Y

A further object of the present invention is the provision of such abanner type tow target made of woven fabric, and which is metallized ina manner so as to produce a target which has the desired radarreliectivity and is still within required weight and dragl limitations.

The foregoing and other objects are attained by the banner type towtarget construction, parts, combinations, and sub-combinations, whichcomprise the present invention or discovery, the nature of which is setforth in the following general statement, and preferred embodiments ofwhich, together with their mode of use, are set forth by way of examplein the following description, and which are particularly and distinctlypointed out and set forth in the appended claims forming part hereof.

The nature of lthe improvements of the present invention may bedescribed in general terms as constituting tow tagetconstructionincluding side by side seam connected continuous liexible panels, eachpanel including longitudinally extending laterally spaced warp strandsand longitudinally spaced filling strands continuously woven with thewarp strands.

Each warp strand is monolament. The filling strands in one end portionor section of the continuous panel are are alternate sets ofmonoiilament filling strands, -and alternate sets of multi-filamentfilling strands. Thus, each panel constitutes a diferentialweavecontinuous open woven fabric panel including `one panel portion .orsection having monoflament warpy strands and monolilaf ment fillingstrands, and another panel portion or section.

l Y Y 3 having monolament warp strands and alternate sets Yof:monolament lling strandsand alternate sets of multilament fillingstrands. Preferably the warp strands are `arrangedinvnarrowerzsidebands-and a'centerband and wider bandsdbetween eachvside band andthe center band, and the warp-strands in the narrower bands-including pairs adjacent each other and forming a smaller mesh weavethantheweave of the wider bands.

By way of example, embodimentsof .the improved banner Vtype tow'targetconstruction and parts of ythe present invention are illustrated intheaccompanying drawings formingpart hereof, in which :Fig 1 is a reducedplanview, diagrammatic .in part, showing a banner type tow-targetincluding the improved differential weavefabric ofthe present invention.

Fig. 2 is an enlarged-fragmentaryplan View showing a detached area ofthe first leading portion or section of the improved bannertype Atowtarget, the rst'leading target portion or section having a irstwovenfabric construction.

Fig. 3 is an enlarged fragmentary plan view showingl a detached area ofthe secondtrailing portion or section of the improved banner type .towtarget, the second trailing target portion or section'having a secondwoven fabric construction.

Fig. 4 is a reduced fragmentary diagrammatic plan View of a length of apanel of the improved fabric for the improved bannerV type tow targetshowing the trans.-Y verse continuous junction between the -rst andsecond target portions or sections, and other details.

Fig. 5 is Yan enlarged k,fragmentary plan view showing -a detached Vareaof the transverse continuous-junction between the rfirst and secondtarget portions or sections, and areas of the rst and second targetportions adjacent the junction.

Similar numerals refer to similar parts throughout the several viewsofthe drawings.

The banner type tow target shown in Fig. 1 is indicated generally byV10, and constitutes a preferred embodiment of the present invention ordiscovery.

The 4tow target 10 is made of a single ply of improved flexible openmesh differential weave fabric hereinafter described in detail, and isan elongated rectangle of such fabric which may have a width of nine(-9) feet and a length of from thirty (30) to forty-ve (45) feet incertain targets.

The elongated rectangular tow target includes a leading edge 11, atrailing edge 12, and transversely spaced side edges 13 and 14. A hitch1S connects `the leading edge 11 in a usual manner with the trailing endof a tow line, not shown, which extends for a mile, more or less, from`a usual towing aircraft, not shown.

The tow target 10 is constituted, from the over-all standpoint, by aiirst leading target portion or section 16 having a transverse junctionindicated by the dot-dash line 17 with a second trailing Vtarget portionor section 18.

As shown, the tow target 10, divided over-al1 into the first and secondportions or sections 16 and 18, is made of three continuouslongitudinally extending fabric panels including a side panel 19 havingthe outer Vside edge 13, 4and at its other edge an Iinside connectingseam S-1 with one edge of acenter panel 20. The other edge of the centerpanel 20 has Yan inside connecting seam S-Z with a sidepanel 21 whichhas the outer side edge 14. M

First: Each of the three panels 19, 20, and 21, inthe irstleading targetportion or section 16, is constituted throughout thev major portion ofits area, by a irst woven fabric construction indicated generally -by22, and shown enlarged in Fig. 2.

Second: Each of the Vthree panels 19,'20, and 21, inv

the'second trailing target portionor section 18 is constitutedthroughout the majorgportion of its area, by a second woven fabricconstruction indicated generallyby Z3, and shownenlarged in Fig. 3,

In each `panel Y19, v20, or 21, eachof therst and second woven fabricconstructions 2,2 and 23 has adifferent weave structure than the other,constituted by common warp strands 24a and 24h, and bydiiferent fillingstrands.

The rst woven fabric construction 22 in any panel such as 19- includes acontinuous :filling strand 25 and a continuous filling strand 26. Thediameter of the strand 25 is less than the diameter of the'strand 26. i

The second woven fabric construction 2.3 in the panel 19, includes acontinuous lling'strand 27 havingA afdiameter which is the'leastdiameter of any filling strand in the entire panel. The diameter of thestrand 27 may c kbe thel same as the diameter of the strand Z5, and thestrand 2-7 preferably is continuous with the strand 25.

A fragment of one of the panels of the target 10, such as the panel 19,is shown diagrammatically in Fig. 4, at the transverse continuousjunction between the rst target portion or section 16' and the secondtargetportion or section 18. In this diagrammatic view, Where thefilling strands 25 and 27,A are shown, the warp strands are removed, tomore clearly illustrate the continuity of the filling strands.

At opposite ends of Fig. 4, the filling strands arevremoved, and eachset of warp strands 24a and 24b `is indicated by a single line. Warpreinforcingis provided in side bands 28 and 29 and center band 30,byfproviding pairs of sets of warp strands 24a and 2411 at'the side ofeach of the fabric openings, instead of the single Vsets of warpVstrands in the wide band 31 between the reinforced bands 28 and 30, andin the wide band vSZ-between the reinforced 'bands 30 and i9.

From a broad standpoint, each of the target portions 16 and 18 may beotherwise described as being constituted by open mesh woven yarn fabric.

Yarn may be furthermore defined as being either a mono-ilament strand ora multi-filament strand, multilament strand yarn being spun.

In open mesh woven yarn fabric, in general for use on'banner type towtargets, the yarn may be constituted by filaments of fibres orcombinations of filaments and/or libres of any desired material ormaterials. Preferably the laments or iibres are constituted by syntheticmaterials such as nylon, Orlon, and the like.

In the present improved minimized drag banner type tow targetconstruction, nylon is a preferred material constituting the fabric yarnor strands. The warp strands 24a and 24h and the lling strands 25 and 27are monolament and preferably are 260 `denier 4 ply spun nylon yarn.

Side-by-side pairs of the monofilament lling strands 25 alternate withside-by-side pairs of the multi-filament strands 26 in the first leadingtarget portion or section 18.

The second trailing portion or section 18 has a length range of fromone-sixth (1/6) to one-third (1A) the total length of the target 10.

The improved banner type tow target `10 Will y at ann altitude of 30,000feet and upwards, and at a speed of 250 knots per hour and upwards,indicated air speed, with required durability, low drag, and othercharacteristics including maximum flexibility at extremely ylowtemperatures, and: ability to be made radar reflective.

Nylon yarnas above -described in the fabricof the improved banner typetow target 10, has a full 2N lenoA weave, and provides the desireddimensional stability and exing capacity lin operation as abovedescribed under temperature extremes `of from 65 P. to +165 4F.

The improved tow target 10 furthermore may'haverall or any portionmetallized to provide a radar reflecting target. v

Whether the tow target 10' is metallized, or not, it 'is desirable tolubricate the target withra lpreparation to provide in the targetmaximurnexing capability, and increased resistance torips and,tears.- H1 fait" Iclaim:

1. A one-piece woven fabric panel for a banner type tow target and thelike, the panel including a rst portion and a second portion adjacentthe tirst portion, each panel portion having opposite ends vand one endof the rst panel portion making a junction with one end of the secondpanel portion, the panel including a plurality of laterally spacedlongitudinally extending warp strands, eac-h warp strand extending theentire length of the rst and second portions of the panel, the rst panelportion having morno-lilamentvlilling strands and multiilament llingstrands, and ythe second panel portion having mono-filament fillingstrands; the lling strands being longitudinally spaced from each otherin the direction of the warp strands; and the mono-filament llingstrands being continuous with each other.

2. A one-piece woven fabric panel for a bannervtype tow target and thelike, the panel including a rst portion and a second portion adjacentthe first portion, each panel portion having opposite ends and one endof the rst panel portion making a junction with one end of the secondpanel portion, the panel including a plurality of laterally spacedlongitudinally extending warp strands, each warp strand extending theentire length of the first and second portions of the panel, the firstpanel portion having mono-lament filling strands and multi-filamenttilling strands, and the second panel portion having monolament fillingstrands; the filling strands being longitudinally spaced from each otherin the direction of the warp strands; and the multi-lilament fillingstrands being continuous with each other.

3. A one-piece woven fabric panelfor a banner type tow target and thelike, the panel including a rst portion ,and a second portion adjacentthe first portion, each vbeing continuous witheach other; and themulti-lament filling strands being continuous with each other.

References Cited inthe le of this patent UNITED STATES PATENTS 2,238,875Manson Apr. 15, 1941 2,298,071 Smith Oct. 6, 1942 2,360,245 McFarlaneOct. 10, 1944 2,511,644 Liss June 13, 1950 2,731,046 ABaohner Jan. 17,1956 2,757,455 Bihaly Aug. 7. 1956 Y FOREIGN PATENTS 132,183

Germany Iuly 14, 1902

